Optical prism and optical transceiver module for optical communications

Abstract

To provide an optical transceiver module comprising an optical prism for optical communications which has mounting portions, a light emitting portion, light receiving portions, a substrate and a sub-mount that are used as the basis of the optical transceiver module, whose configuration is compact with reduced components which are accurately mounted.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates the configuration of an optical transceiver module, a first embodiment of the present invention.

FIG. 2 is an enlarged cross section view of the optical transceiver module shown in FIG. 1. FIG. 2 shows the individual configurations and mutual relations of the module's substrate, sub-mount structure and main components (laser diode, photo diode and optical fiber).

FIGS. 3A (A)-(D) are provided to explain the configuration of the optical communication prism according to the first embodiment.

FIGS. 3B (A)-(D) are provided to explain a variation of the first embodiment shown in FIGS. 3A(A)-(D). While the optical communication prism of the first embodiment is configured by combining a right-angled prism with a half-ball prism, the optical communication prism of this variation is configured by combining a right-angled prism with another right-angled prism which is in surface symmetry to the other right-angled prism.

FIGS. 4A and 4B are perspective diagrams to explain how the optical components, namely a photo diode, a laser diode and an optical communication prism are mounted on the substrate and the sub-mount.

FIG. 5A shows a cross section of components of an optical communication prism, a second embodiment. FIG. 5B shows how a wavelength division multiplexing film 31 is attached to the slant surface. FIG. 5C shows the optical prism assembled after FIG. 5B.

FIG. 6 shows a cross section of a third embodiment. This figure corresponds to FIG. 2 for the first embodiment.

FIG. 7 shows a cross section of a fourth embodiment. This figure corresponds to FIG. 6 for the third embodiment.

FIG. 8 shows a cross section of a fifth embodiment. This figure corresponds to FIG. 6 for the third embodiment.

FIG. 9A schematically shows the configuration of a sixth embodiment. This figure corresponds to FIG. 1 where the configuration of the first embodiment is schematically shown. FIG. 9B shows a cross section of the sixth embodiment. This figure corresponds to FIG. 6 for the third embodiment.

Claims

1. A composite optical prism for optical communications that is assembled by combining a first right-angled prism and a hemisphere lens so that the slant surface of the first right-angled prism and the slant surface of the hemisphere lens face each other through a wavelength division multiplexing filter sandwiched between the first right-angled prism and the hemisphere lens, wherein: at least one of the two mutually perpendicular rectangular surfaces of the first right-angled prism is configured to have a lens function; andeach side of the composite optical prism is provided with a mounting support that extends perpendicularly to an optical path of light incoming onto and outgoing from the composite optical prism.

2. The composite optical prism for optical communications according to claim 1, wherein: the hemisphere lens is replaced by a second right-angled prism, the first and second right-angled prisms being in plane symmetry with respect to the slant surfaces; andsurfaces of each right-angled prism on which or from which light is incident or emitted are configured to have a lens function.

3. The composite optical prism for optical communications according to claim 1, wherein each of the first right-angled prism and the hemisphere lens is provided with a positioning portion on the slant surface thereof for defining the relative position thereof.

4. The composite optical prism for optical communications according to claim 2, wherein each of the first and second right-angled prisms is provided with a positioning portion on the slant surface thereof for defining the relative position thereof.

5. The composite optical prism for optical communications according to claim 1, wherein the composite optical prism has an air gap formed between the wavelength division multiplexing filter and either of the slant surface of the first right-angled prism or the slant surface of the hemisphere lens.

6. The composite optical prism for optical communications according to claim 2, wherein the composite optical prism has an air gap formed between the wavelength division multiplexing filter and either of the slant surface of the first right-angled prism or the slant surface of the second right-angled prism.

7. The composite optical prism for optical communications according to claim 1, wherein each side surface of the first right-angled prism is an isosceles right-angled triangle.

8. The composite optical prism for optical communications according to claim 2, wherein each side surface of the second right-angled prism is an isosceles right-angled triangle.

9. The composite optical prism for optical communications according to claim 1, wherein each side surface of the first right-angled prism is a scalene right-angled triangle.

10. An optical transceiver module comprising: a substrate;a square U-shape sub-mount disposed on the substrate;a light emitting portion disposed on the top portion of the sub-mount;a light receiving portion disposed on the substrate; anda composite optical prism for optical communications that is assembled by combining a first right-angled prism and a hemisphere lens so that the slant surface of the first right-angled prism and the slant surface of the hemisphere lens face each other through a wavelength division multiplexing filter sandwiched between the first right-angled prism and the hemisphere lens, wherein at least one of the two mutually perpendicular rectangular surfaces of the first right-angled prism is configured to have a lens function, and each side of the composite optical prism is provided with a mounting support that extends perpendicularly to the optical path of light incoming onto and outgoing from the composite optical prism,wherein the mounting supports of the composite optical prism are held and positioned on top of the respective wing portions of sub-mount so that light emitted from the light emitting portion is incident on the composite optical prism and the light emitted from the composite optical prism is incident on the light receiving portion.

11. The optical transceiver module according to claim 10, wherein each of the first right-angled prism and the hemisphere lens is provided with a positioning portion on the slant surface thereof for defining the relative position thereof.

12. The optical transceiver module according to claim 10, wherein the composite optical prism has an air gap formed between the wavelength division multiplexing filter and either of the slant surface of the first right-angled prism or the slant surface of the hemisphere lens.

13. The optical transceiver module according to claim 10, further comprising: guide marks provided on the top portion of the sub-mount for positioning the light emitting portion;guide marks provided on the substrate for positioning the light receiving portion; andguide marks provided on top of the wing portions of the sub-mount for positioning the mounting supports.

14. The optical transceiver module according to claim 10, wherein in addition to the wavelength division multiplexing filter provided between the slant surface of the first right-angled prism and the slant surface of the hemisphere lens, a wavelength division multiplexing filter is disposed in the optical path on the light incidence side of the light receiving portion provided on the substrate.

15. The optical transceiver module according to claim 10, wherein: the hemisphere lens is replaced by a second right-angled prism, the first and second right-angled prisms being in plane symmetry with respect to the slant surfaces; andsurfaces of each right-angled prism on which or from which light is incident or emitted are configured to have a lens function.

16. The optical transceiver module according to claim 15, wherein each of the first and second right-angled prisms is provided with a positioning portion on the slant surface thereof for defining the relative position thereof.

17. The optical transceiver module according to claim 15, wherein the composite optical prism has an air gap formed between the wavelength division multiplexing filter and either of the slant surface of the first right-angled prism or the slant surface of the second right-angled prism.

18. The optical transceiver module according to claim 15, wherein in addition to the wavelength division multiplexing filter provided between the slant surface of the first right-angled prism and the slant surface of the second right-angled prism, a wavelength division multiplexing filter is disposed in the optical path on the light incidence side of the light receiving portion provided on the substrate.

19. The optical transceiver module according to claim 10, wherein the substrate and the sub-mount are formed as a single component.

20. The optical transceiver module according to claim 13, wherein the mounting supports of the composite optical prism are provided with alignment marks corresponding to the marks provided on the sub-mount.